Little is known about the biology of this species. Like other squirrel monkeys it is active during the day and is arboreal (6). This small primate is omnivorous and spends most of the morning and afternoon foraging in the trees for fruits, leaves, buds, gums, insects and small vertebrates (7). It has been reported that this species recognises the leaf-tents constructed by some fruit-eating bats and attacks these structures to extract the bats roosting within (8). Red-backed squirrel monkeys are social primates. They live in large multi-male / multi –female groups of about two-dozen individuals on average, and travel between 2.5 and 4.2 km a day, with home ranges of 0.175 km² (2) (6) (9). Reproduction is seasonal, with mating occurring in January and February (2), with single births occurring at the period of greatest food availability. This ensures there will be adequate food available for the mothers and their young, and requires less time spent foraging (10).